Oxidation and reduction - Jamb Chemistry Past Questions and Answers

Question 76:

• JAMB 2006

The ion that will give a white precipitate with aqueous NaOH and soluble in excess of the base is

A. Ca²⁺
B. Mg²⁺
C. Zn²⁺
D. Cu²⁺

Question 77:

• JAMB 2006

The ion that can be used as an oxidizing agent is

A. Au³⁺
B. Fe³⁺
C. ClO^-
D. Ca²⁺

Question 78:

• JAMB 2006

In which of the following is the oxidation number of sulphur equal to -2?

A. SO₃
B. S₈
C. H₂S
D. SO₂

Question 79:

• JAMB 2007

Cu²⁺_(aq) + 4NH_3(g) ↔ [Cu(NH₃)₄]²⁺_(aq)
In the reaction above, what is the effect of precipitating Cu²⁺_(aq) as CuS_(s)?

A. NH_3(g) concentration will decrease
B. More NH_3(g)will be generated
C. The equilibrium will shift to the right
D. There will be no effect

Question 80:

• JAMB 2007

The oxidation state of oxygen in tetraoxosulphate (VI) acid is

A. -4
B. -2
C. +4
D. -8